Method and apparatus for mechanically heating a mixture of substances

ABSTRACT

A method for mechanically heating a liquid mixture of substances is described. In a liquid-ring pump ( 1 ), a foam phase is compressed and the compression heat is transferred to the mixture of substances. An apparatus designed as a liquid-ring pump ( 1 ) for mechanically heating a liquid mixture of substances is also described. Said liquid-ring pump ( 1 ) comprises an impeller ( 12 ) eccentrically arranged in a cup-shaped pump housing ( 11 ) as well as a tangential suction port ( 13 ) and a tangential delivery port ( 14 ). A gas port ( 15 ) for introducing an inert process gas extends into the suction port ( 13 ) and/or into the cup-shaped pump housing ( 1 ).

The invention relates to a method and a device for mechanical heating of a substance mixture.

From DE 10 2005 056 735 83 is known a high-performance chamber mixer for catalytic oil suspensions to be used as a reactor for the depolymerization and polymerization of hydrocarbon residues into middle distillates in the circuit. The pump efficiency of the high-performance chamber mixer is low, so that the mechanical energy applied is, for the most part, converted into mixing and frictional energy.

From DE 2008 009 647 A 1 is known a sludge reactor pump for simultaneous transport of solids, liquids, vapours and gases in a common flow stream. The sludge reactor pump is a combination of a fluid ring vacuum pump and a radial pump.

Solid and fluid materials are conveyed to the circumference of the pump, while the gases and vapours are separated in the interior.

The object of the present invention is to provide an improved method and an improved device for the input of energy into a fluid substance mixture and to supply the latter.

According to the invention, this object is achieved by a method for the mechanical heating of a fluid substance mixture, whereby a foam phase is produced by a fluid ring pump, and the foam phase is compressed in order to transfer the compression heat to the substance mixture.

The object is further achieved by a device in the form of a fluid ring pump for the mechanical heating of a fluid substance mixture, whereby the said fluid ring pump comprises an eccentrically-arranged impeller as well as a tangentially-arranged suction nozzle and a tangentially-arranged pressure nozzle in a cup-shaped pump housing, whereby there is a gas nozzle to feed an inert process gas into the suction nozzle and/or the pot-shaped pump housing.

The method and device according to the present invention allow very effective energy input into the fluid substance mixture, whereby, contrary to the reservations of a person skilled in the art, a foam phase is produced in the fluid ring pump. It has been found that the energy expended for the production of the foam phase is directly converted into heat energy in the breakdown of the foam phase, so that introduction losses that occur in the external heating of the fluid may be avoided.

It may be arranged that the substance mixture is a mixture of oil, residues and a catalyst. The oil and residues may be waste products to be recycled. As residues, organic waste such as occur in agriculture and forestry may be used.

The substance mixture can be circulated in a circuit. It may be enriched with hydrocarbons during the continuous or discontinuous addition of residues during the cycle. The residues may be partially or completely dissolved in oil.

It may be arranged that he foam phase is produced by the introduction into the process mixture of an inert gas under low pressure.

The process gas may be introduced into the fuel mixture upstream of the fluid ring pump.

It may be arranged that the process gas is introduced into the fluid ring pump in the fuel mixture.

In an advantageous embodiment, it may be arranged that the proportion of the foam phase is from 10 to 30% by volume, preferably from 10 to 25% by volume.

The proportion of the foam phase may be so selected that a fluid ring is formed on the inner periphery of the fluid ring pump, In this way, the flow rate of the fluid ring pump is ensured despite the entry of foam.

It may be arranged that the proportion of the foam phase is determined by temperature measurement upstream and downstream of the fluid ring pump and the resulting energy input into the mixture calculated.

Further sub-claims cover the device.

It may be arranged that the gas nozzle is arranged with its axis parallel to or in alignment with the axis of rotation of the impeller.

The outlet of the gas nozzle may be formed as a slot nozzle.

In an advantageous embodiment, it may be arranged that the width of the slot is greater than the diameter of the gas nozzle.

The invention will now be explained in more detail by means of embodiments. The figures show:

FIG. 1 shows a schematic perspective view of an exemplary embodiment of a device according to the invention;

FIG. 2 shows a schematic sectional view of the device of FIG. 1;

FIG. 3 shows a block diagram of an exemplary application of the device of FIGS. 1 and 2

FIGS. 1 and 2 show an embodiment of a device in the form of a fluid ring pump 1 for the mechanical heating of a fluid substance mixture, whereby the liquid ring pump 1 comprises an eccentrically arranged impeller 12 as well as a tangentially-arranged suction nozzle 13 and a tangentially-arranged pressure nozzle 14 in a cup-shaped pump housing 11. A gas nozzle 15 feeds into the suction nozzle 13. To this end, the gas nozzle 15 has a slot 15 s that is arranged in the axial region of the suction nozzle 13 and opens into it.

The pump housing 11 is cup-shaped. Because of the eccentric arrangement of the impeller 12 in the pump housing 11, the ends of the blades of the paddlewheel-shaped impeller 12 are at a varying distance from the inner wall of the pump housing 11 as a function of the rotational position. The fluid ring pump 1 is a rotary pump, i.e. a continuous flow machine. Fluid entering the fluid ring pump 1 via the suction nozzle 13 is entrained by the rotating impeller 12 and is forced outwards along a circular path because of the centrifugal forces occurring. The kinetic energy of the fluid received in this way increases the pressure within the pump housing 11 and compresses the fluid in the pressure nozzle 14. The inert gas entering the fluid through the gas nozzle 15 produces a foam phase in the fluid which also absorbs the kinetic energy, whereby the gas trapped in the foam bubbles is compressed and heated. Intensive heat transfer takes place between the foam bubbles and the fluid so that the fluid is heated. The gas nozzle 15 is arranged with its axis parallel to or in alignment with the axis of rotation of the impeller (12).

FIG. 3 shows an embodiment for use of the fluid ring pump 1

The fluid ring pump 1 is used as a supply and mixing pump in a KDV plant 2 for catalytic pressure-free depolymerization. At a process temperature of 280 to 320° C. in KDV plant 2, long-chain hydrocarbons are split into short-chain hydrocarbons under the action of a catalyst, such as those contained in diesel oil. For this purpose, a fluid substance mixture containing oil, residues and a catalyst at the process temperature, is fed into the circuit by the fluid ring pump 1.

The foam phase substance mixture 29 formed in the fluid ring pump 1 is introduced into a separator 21, for example in the form of a funnel-shaped container, on whose inner wall the mixture runs down and thereby evaporates. The diesel vapour 24 d flows into a distillation column 22, which is arranged above the separator 21, and then passes into a condenser 23 downstream of the distillation column 22. Condensate thus forms in the condenser 23 in the form of diesel oil 24, which is collected in a product tank 25. The product tank 25 is vented using a vacuum pump 26, whereby the exhaust gas 27 accumulated above the diesel oil 24 is partially supplied to the gas nozzle 15 of the fluid ring pump 1. To begin the process, an inert gas such as nitrogen is fed from a compressed gas container in place of the exhaust gas.

A central container 28 is arranged under the separator 21, into which the evaporated substance mixture 29 r flows. The central container 28 may have an inlet nozzle 28 e though which residual material 30 from a hydrocarbon residue container 31 may be introduced into the substance mixture 29 r. The residue 30 is dissolved in the evaporated substance mixture 29 r and homogeneously distributed on the way through the central container 28. However, the residue 30 may be also fed back into the substance mixture circuit downstream behind the central container 28. In this way, an enriched substance mixture 29 a is obtained, which is supplied to the suction nozzle 13 of the fluid ring pump 1 to close the substance mixture circuit,

Sediment particles 32 precipitated from the substance mixture can be removed at the bottom of the central container 28, and may be used as fuel or discarded.

The optimum operation of the fluid ring pump 1 may be adjusted according to two methods.

Firstly, the proportion of the foam phase may be so selected that a fluid ring is formed on the inner periphery of the fluid ring pump 1. Secondly, the proportion of foam phase may be determined from the energy input into the substance mixture. Two temperature sensors are provided for this purpose. A first temperature sensor 33 is arranged downstream of the fluid ring pump 1 in the substance mixture pipe. A second temperature sensor 34 is arranged upstream of the fluid ring pump 1 in the substance mixture pipe. The signals from both temperature sensors 33, 34 are evaluated in a control device 35, and a control signal is formed for a control valve 36 that is arranged in the connecting pipe between the vacuum pump 26 and the gas nozzle 15 of the fluid ring pump 1 in order to control the quantity of the gas intended for the foam production.

It has proved effective when the proportion of foam phase is from 10 to 30% by volume, preferably from 10 to 25 vol %,

REFERENCE NUMERAL LIST

-   1 fluid ring pump -   2 KDV plant -   11 pump housing -   12 impeller -   13 suction nozzle -   14 pressure nozzle -   15 gas nozzle -   15 s slot orifice -   21 evaporator system -   22 distillation column -   23 condenser -   24 diesel oil -   24 d diesel vapour -   25 product tank -   26 vacuum pump -   27 exhaust gas -   28 central container -   28 e inlet nozzle -   29 substance mixture -   29 a enriched substance mixture -   29 r evaporated mixture -   30 residue -   31 residue—reservoir -   32 sediment particles -   33 first temperature sensor -   34 second temperature sensor -   35 controller 

1. A method for the mechanical heating of a fluid substance mixture, wherein a foam layer is produced in a fluid ring pump and the foam phase is compressed in order to transfer the heat of the compression to the substance mixture.
 2. A method according to claim 1, wherein the mixture is an oil, residue and catalyst mixture.
 3. A method according to claim 1, wherein the mixture is circulated in a circuit.
 4. A method according to claim 1, wherein the foam phase is produced by the introduction of an inert process gas under low pressure into the substance mixture.
 5. A method according to claim 4, wherein the process gas is introduced into the substance mixture upstream of the fluid ring pump.
 6. A method according to claim 4, wherein the process gas is introduced into the substance mixture in the fluid ring pump.
 7. A method according to claim 1, wherein the proportion of the foam phase is from 10 to 30% by volume, preferably from 10 to 25% by volume.
 8. A method according to claim 1, wherein the proportion of the foam phase is so selected that a fluid ring is formed on the inner periphery of the fluid ring pump.
 9. A method according to claim 1, wherein the proportion of the foam phase is determined by temperature measurement upstream and downstream of the fluid ring pump and the energy transfer to the substance mixture is thus calculated.
 10. A device formed as a fluid ring pump for the mechanical heating of a fluid substance mixture, whereby the fluid ring pump has an eccentrically-arranged impeller as well as a tangentially-arranged suction nozzle and a tangentially-arranged pressure nozzle in a pot-shaped pump housing, wherein a gas nozzle for introducing an inert process gas opens into the suction nozzle and/or in the pot-shaped pump housing.
 11. A device according to claim 10, wherein the gas nozzle is arranged with its axis parallel to or in alignment with the axis of rotation of the impeller.
 12. A device according to claim 10, wherein the outlet of the gas nozzle is formed as a slot.
 13. A device according to claim 12, wherein the width of the slot is greater than the diameter of the gas nozzle. 